| abstract |
A stopper for a blood collection tube adapted to receive whole blood for centrifugal separation into its relatively light and heavy phases. The stopper is provided with a coating which prevents red blood cells from adhering to it so as to avoid red cell contamination of the lighter phase after phase separation. The stopper is coated with a cationic binding agent, such as tridodecylmethylammonium chloride, and then with an anionic anticoagulant such as dextran sulfate. A lubricant, such as silicone oil, is applied to the coated stopper to facilitate insertion of the stopper into the tube. |